One of the key moments in the third Democratic primary debate was when Sen. Elizabeth Warren (D-Mass.) called for eliminating the Senate's filibuster rule, the outmoded 60-vote threshold needed to proceed to a final vote on nearly all legislation. In the American political system, that gives the political minority in the Senate the ability to quash almost any laws they don't like. Warren, who was one of the first candidates to call for its elimination, made a forceful case to "roll back" the rule. But when the moderators posed the same question to Bernie Sanders (I-Vt.), he demurred.

After saying he wouldn't eliminate the filibuster rules, he went on to claim that he had other ways to deal with Senate obstruction. "I will not wait for 60 votes," Sanders said, "and you can do it in a variety of ways. You can do that through budget reconciliation law. You have a vice president who will, in fact, tell the Senate what is appropriate and what is not, what is in order and what is not," he said. His plan is to use the even more byzantine "budget reconciliation" process to pass his signature Medicare-for-all bill, as well as, presumably, critical climate legislation and other prominent planks in his platform.

The exchange between Warren and Sanders passed quickly. A volley about Senate rules is not likely to be the moment everyone remembers about this debate. But its brevity belied its importance, because underneath questions about majority rule in the Senate is a bigger and more difficult conundrum: Democrats aren't getting 60 seats next year, so unless they make some procedural changes, Senate Majority Leader Mitch McConnell (R-Ky.) will continue to exercise his veto over any important policy changes, even from the minority. So how, even under the most optimistic scenarios, would the next Democratic president get anything done?

Reconciliation is one of those words that means something completely different in D.C. than it does in real life. In a small number of cases per year, the Senate may use simple majority voting rules to pass legislation that affects revenue, the debt, or spending. After Democrats lost the critical 60th vote in the Senate following the death of the late Sen. Ted Kennedy (D-Mass.), reconciliation allowed them to pass a handful of changes (although not most of the bill) to the Affordable Care Act.

The way Senate rules have thwarted majorities in the past actually did come up in this debate. Moderator Jorge Ramos, after a contentious immigration exchange with former Vice President Joe Biden, asked former Secretary of Housing and Urban Development Julián Castro why Democrats weren't able to get immigration reform passed even when they controlled the Senate and the House in 2009-2010. Either could have used the moment to say that, under the kinds of simple majority rules used in every other legislature on the planet, it would have gotten done. So would a public option for the Affordable Care Act. So would dozens of other important laws that died under the relentless mortar fire of a rule that empowers political minorities to endlessly obstruct the lawmaking power of the majority. But Biden, ever the Senate traditionalist, refused to go there, and Castro chose to light into Biden.

When it comes to the filibuster, Warren has the simpler and more persuasive case here. The filibuster is an anti-democratic rule, found nowhere in the American Constitution and lacking even the most rudimentary theoretical backing. Most Americans not only do not revere the filibuster, they don't even know what it is. There can't be a real, lasting backlash against eliminating something that few understand. While there would be the predictable, weeks-long, post-kill-filibuster moral panic on Fox News, the procedural escalation would quickly be forgotten, just as it was when Democrats used reconciliation to pass the Affordable Care Act.

The best case for Warren's filibuster abolition plan is this: Getting rid of supermajority requirements altogether frees the Senate to pass any legislation that it can muster 50 or 51 votes for (depending on who controls the White House) at any time. Under a unified Democratic government, that means that Congress could, in theory, nimbly address any manner of challenges without resorting to the procedural gimmicks required to pass legislation under reconciliation.

Not so with the Sanders plan. It seems Sanders intends to cram loads of progressive legislation into the maximum of three reconciliation bills that can pass through Congress in any given year. While that's obviously a better plan than hoping that the power of persuasion can finally reach McConnell, it is unnecessarily convoluted, in both practically and politically destructive ways.

Remember the hullabaloo that followed the use of reconciliation to pass the Affordable Care Act? Republicans acted as if Democrats had dissolved Congress or seized power in a military coup. Under the Sanders plan, Republicans and their allies will strike this pearl-clutching pose in the aftermath of every single piece of important legislation passed through reconciliation over the four or eight years of a Sanders administration. More importantly, using reconciliation procedures imposes real limitations on the Democratic agenda.

Rules stipulate that reconciliation may not be used to increase the deficit, and any bills passed under its aegis must make affecting revenue one of their principal goals. Sanders believes the vice president can simply instruct the Senate parliamentarian to disregard these rules. Maybe. But Congress may only pass one bill per year under reconciliation for spending, revenue, and the federal debt ceiling, meaning that Congress could only pass three meaningful tranches of legislation a year. That's not a Senate rule, but rather part of the original legislation establishing the reconciliation process in 1974.

Journalist Ryan Grim claimed during the Houston debate that the reconciliation gambit is more realistic than finding 51 votes to torch the filibuster, and so the Sanders plan is more practical. How will you convince Sen. Joe Manchin (D-W.V.), a conservative Democrat who might be the pivotal vote for all kinds of things starting 2021, to eliminate a longstanding Senate rule? But that objection could be turned around in so many ways — a world in which Manchin is the Senate's swing vote is also a world in which the more expansive versions of Medicare-for-all are probably dead anyway.

This might, of course, be little more than an academic debate. If a Democratic president doesn't bring a Democratic Senate majority with them — a serious risk even in pretty optimistic scenarios — then the president will have to constantly push the legal limits of executive action and ignore a Congress with Republicans in control of one or both branches altogether. And you can dream on how a Democratic president might use the newly expansive powers of the executive branch while also worrying that the Supreme Court might develop a different view of executive power when tussling with a Democratic rather than a Republican president.

For now though, it's worth imagining and arguing over a world in which Democrats seize unified control in Washington next year. And as long as we're in that imaginative realm, there aren't very many good reasons to keep the filibuster around. An America where genuine progress is being made through Congress is, you might say, irreconcilable with a Senate adhering to its counter-majoritarian filibuster rules. Warren gets that, and Sanders doesn't.